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Is That An OC-768 In Your Pocket?
bdigit writes: "Qwest communications using Nortel Networks OC-768 was able to transfer 40Gbps over 435 miles(700 km) breaking the record for the fastest land speed record. Qwest has plans to begin deploying OC-768's in quarter three of 2001." Note: if they need beta testers, just lemme know! I can write a mean bug report ("My pr0n is only getting 30gps! Please fix!")
This message posted by CmdrTaco via U.S. Post Office.
T1,T3 are transmission rates that descibe electrical interfaces. A T1 link is 1.5mb ( bits )
T3 = 45mb. OC ( optical carrier ) is a BellCore
description of transmission in SONET networks. ( Synchronous Optical Network ).
The speed of OC-n is derived from the number of interleaved STS streams. STS-1 is 51mb per second
All OC-n rates ( lowest is OC-3 which sts-1x3 ) are derived from a multiple of this.
OC-768 = 768xSTS1 rate = 39168mb per second
OC-48 = 48xSTS-1 rate = 2448mb per second
OC-3 = 3xSTS-1 rate = 153mb per second
OC-n rates can be described as concatenated ( a fat pipe ). or Channelized whereby an OC pipe contains multiple channels ( STS payloads )each
of which can contain different payloads ( packets or atm cells ).
Oc-3c is a concat. fat pipe.
Oc-3 is a channelized pipe.
When I was your age we had to walk ten miles uphill both directions to get our email, and we loved it.
lol - i'm wearing my 'chicks dig unix' T-shirt with some cargo pants. and a Gameworks hat from seattle...
there are only two things that get me hard bro - naked women that i'm about to have sex with and the 2.4.0 kernel - this article wasn't about either.
FluX
After 16 years, MTV has finally completed its deevolution into the shiny things network
"It is seldom that liberty of any kind is lost all at once." -David Hume
OC-768 exists for short haul ATM and SONET connections inside a data centre. That is not a big deal in the communications world.
/. posted links to a real news story, rather than print a company press release with no further informations for us to look at. This story surface a few months ago when a european partner of Qwest and Nortel were showing the technology at a trade show in Germany. They had a couple of spools of fibre totalling about 20kms, and were pumping some incredible level of data across it. They had also done a real world test between two German cities with a fibre running along side some train tracks.
Getting OC-768 DWDM with all of its little tricks to run for such a long distance between end points makes the promise of bigger and better backbones a reality. There are a ton of technical problems keeping the leading and trailing edges of the pulses of every different wavelength of light from degrading and interfering, and somehow managing to recover all the signals at the far end. 700Kms covers most any reasonable distance in Europe.
It would be nice if
the AC
Hemos is like...sci-fi fans;he thinks technology is cool, but he hasn't bothered to understand the science it's based on
From the useless stats dept.
40 Gbits/sec = 216 Terabytes in 12 hours.
If you put 1800 120GB DDS4 tapes in FedEx baggies you will move the same about of data (latency is not so good but that's not the point :-)
Never underestimate the bandwidth of a truck load of tapes.
Never underestimate the bandwidth of a truck load of tapes
Waddayaneed more than 30gps for? a realtime tomographic video of her insides?
perl -e 'fork||print for split//,"hahahaha"'
That's some nice bandwidth. If only having access to high bandwidth lines didn't cost retarded amounts of money, the Internet would be a far better place than it is now. Just imagine, if the last-mile bit was solved with high(er)-bandwidth lines everywhere, one wouldn't need cable or telephones..
Utopia? Nah. Better? Yes.
2 clicks in and there's a whole page of information about this "record breaking" event.8 8
http://www.qwest.com/about/media/story.asp?id=2
Yeah, it wouldn't be horribly expensive or anything for the cable company to rewire its entire system so that there is a dedicated line running from the cable company to each and every house it serves, now would it? And, surely, if it was, they wouldn't happen to pass that expense on to the customer, because they are decent people who don't care if they lose money, as long as the customer is happy, right?
Friends don't let friends use multiple inheritance.
Just so you know, the fastest record overall is 1.1 terabits per second over fiber. However, it was done in a labratory with the fiber coiled around pole. As for Qwest, I think these guys are just great. They have tons of fiber and are provide bandwidth to 70% of major cities. If they upgrade there network significantly with these lines, the internet in general should be much less congested.
A deep unwavering belief is a sure sign you're missing something...
One thing that Ive never had adequately explained to me is grades of fiber..
It has something to do with bran muffins and being regular... Try this one
Our 56K will still outperform any 40Gbps lines in the future because by MS .net server will be in a perpetual crashed state.
Actually at this point, you are mistaken. I was just reading an article on optical amplifiers. Basically you dope a length of fiber with rare-earth elements, use a laser to pump the elements in an excited state. Then when the signal comes in on one end, it causes a percentage of the excited atoms to lase, resulting in an increase of signal. It's not a whole lot different from how a HeNe laser tube works. Since it's all optical, you don't have a speed bottleneck. The big issue now is how to pump more power into that fiber. (More power = longer distances) They are approaching the ability to push 1 watt of power into the fiber. That may not sound like much, but when you push it through single-mode fiber, the resulting energy density is ~10 times that of the surface of the sun. If the glass isn't "perfect" it can start to melt. If you don't have the fiber attenuated by the time it gets to the far end, you can actually damage your detector in these new systems.
Ain't quantum mechanics fun?
Can anyone explain to everyone here how the T1 & T3 and OC3 rates work?
...). Europe did something similar but incompatable, of course. B-)
...
Sure. I've been architecting an ASIC for an "edge router" for the last year, and I've had to live and breathe this stuff.
ENORMOUSLY simplified:
DSn (n= 1, 1C, 2, 3, 4NA) refer to data format standards. Tn (n= 1, 1C, 2, 3, 4NA) refer to standards for carrying those formats on wires. Similarly, STS-n and OC-n refer to the SONET standards for data formats and carrying them on an optical fiber, respectively.
These are standards for US/Canada. Japan is virtually identical (Jn; n=1,
For data only a few are in common use. These are:
Unchannelized T1/DS1
Unchannelized T3/DS3
STS-n/OC-n n=1, 3, 12, 24, 48,
The basic quantum of data is 8,000 8-bit bytes ("octets") per second (nicknamed a "DS0"). This is 64,000 bits per second, enough for one phone call. (Some phone equipment steals one bit out of the byte every 6 frames for signaling {ring, dialing, off-hook}, making one of the bits untrustworthy, which is part of why modems maxed out at about 56,000 BPS rather than 64,000.) And yes, that IS a decimal 8,000, not 8K.
DS1/T1 packs one bit of overhead and 24 bytes of payload into a 193-bit "frame". A T1 feed will typically be "unchannelized" - you get to use the 24 bytes. So the data rate is 1.544 Mhz, and you get to use 1.536 Mbps. For PPP the data will typically be HDLC packets, but some applications will use ATM cells (stuffed with packets fragmented according to the AAL5 standard). The data packaging and protocols will consume some of that remaining bandwidth.
(ISDN come in two flavors. One ("primary rate"?) uses a T1 but steals one of the 24 DS0s for signaling. The other ("base rate"?) is a format similar in style to a T1, but with the payload stripped down to 2 DS0 channels plus a narrow signaling channel. ISDN makes "digital phone calls" of DS0 bandwidth. Typical equipment can make multiple calls and use MultiLink PPP to combine them into a bigger pipe.)
Higher rates were originally designed to pack up and carry lower rates. A "channelized" DS2 carries 4 DS1s, a DS3 carries 7 DS2s (i.e. 28 DS1s). But if you buy a point-to-point DS3 you can also use it "unchannelized":
An unchannelized DS3/T3 runs at 44.736 MHz. One bit in 85 is used for overhead, and the rest are payload, so you get about 44.21 Mhz raw bandwidth. Again your typical PPP feed will use HDLC, but an ISP talking to a DSLAM will use ATM cells. If he expects to do voice-over-packet he might use the "PLCP mapping" of the ATM cells into the DS3 to trade away about 4% of the bandwidth to pass timing information to the DSLAM. (T1 clock rates are tightly synchronized, to keep the DS0s - which are the voice sampling rate - synchronized, preventing "clicks" in your phone. T3 rates are very accurate, but NOT tightly synchronized. A click every three days is acceptable. A click every few minutes is not.)
An OC-1/STS-1 has, per second:
- 8000 frames, each composed of
- 9 rows, each composed of
- 90 octets.
For a total bit rate of 51.84 Mhz. The first three octets in each row are used for overhead related to alligning and tranporting the data. The rest is payload. Depending on what the payload IS, perhaps one byte per row might be used for overhead there, as well.
The payload is allowed to "float" within the 87*9 non-overhead bytes of the framing structure, so that when it hops from one framing to another the box where it hops doesn't need a big buffer to get it alligned, and so things don't break if the boxes' clocks drift. Part of the 3-bytes-per-row overhead is a pointer showing where the start of the payload's frame is currently located within the STS frame.
You'll notice that the STS-1 rate is similar to the T3 rate, and that's NOT an accident. The SONET standard was designed to interface with the existing phone network, and the T3 was the layer where they started. One of the many possible payloads of an OC-1/STS-1 is a DS3. So for raw usable data rates think OC-1 = T3. You'll be dead on if it's carrying a T3, and real close if it's carrying something else.
An STS-n/OC-n is N times the STS-1/OC-1 rate, and carries N times the payload. Unlike the DSn hierarchy, which has separate standards for each layer, SONET defines a general mechanism for higher rates. So the particular rates that are of interest are the ones for which equipment manufacturers chose to build the equipment.
The format of an STS-n is just N STS-1s, with their framing alligned, interleaved by byte, i.e. the first byte from STS-1 number one, then the first from from STS-1 number 2, and so on for N bytes. Then the second byte from STS-1 nubmer 1, and so on forever.
There are two flavors of combining them. An STS-n/OC-n is N separate STS-1/OC-1 channels. An STS-nC/OC-nC is a single channel: There are still N STS-1 framing strucures, but a single payload is smeared out across all of them.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
DrEldarion wrote "They've already done experiements where they put electrodes on a guy and he was able to move a cursor around the screen just by thinking about it... (sorry, I forgot where I read that... no link :/ ) "
Here's some links to articles about that:
Also, a Slashdot article:
" Anyways, I'm sure that eventually you'll just have a DataJack in your head (just like in ShadowRun!) where you'll just plug in a cable and you're all set. "
Sounds like fun to me! ;-)
Impossible means no one's done it yet.
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Impossible means no one's done it yet.
"In my day, sonny, we only had a 64kbps connection to my house. Thats right. And that's when I was already an adult. Now every house comes with a standard 40Gbps line. Aren't you special. You don't know what its like to have to wait for your keystrokes to be echoed back to your terminal screen. Oh, sorry, you don't even know what a keyboard is do ya. Get outta here."
The next site to slashdot will be ready soon, but subscribers can beat the rush and start slashdotting it early!
Where's the obligatory conversion of 40Gbps into X Libraries of Congress/second?
There's a bandwidth chart at the bottom of Bandwidth.com.
BilldaCat
Of course, as this part of a tutorial indicates that higher bitrates allow for fewer channels, getting 80 might not be possible, so we may just have to settle for `only' 160gbps.
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Bruce
Bruce Perens.
You obviously don't have any idea of what equipment transporting these amounts of data costs. And how expensive it is to set up a local DSL-POP.
bottm-line: broadband-services costs more money than consumers are willing to pay, and since this is a market-driven world, that will only change when either of two happens:
1. People are willing to pay more to get more
2. Prices on equipment drop
-- Andreas
Actually, you'll never see OC-1024s. The n in OC-n is an integer, roughly equivalent to the number of DS-3s of bandwidth of the connection. For technical and historical reasons, n will always be 3*(2^x), where x is an integer.
Therefore, the next step up from OC-768 (n=3*2^8) is OC-1536 (n=3*2^9).
Dewey, what part of this looks like authorities should be involved?